package hook

import (
	"bytes"
	"encoding/hex"
	"fmt"
	"os"
	"path"
	"time"
	"tunnel/pkg/config"
	"tunnel/pkg/server/env"
	"tunnel/pkg/server/opts"
	"tunnel/pkg/server/queue"
)

const teeDefaultFile = "/tmp/tunnel/dump"

type tee struct {
	f *os.File
	h *teeHook
}

type teeHook struct {
	file string
	time bool
}

func (t *tee) dump(s string, p []byte) error {
	var out bytes.Buffer

	if t.h.time {
		now := time.Now().Format(config.TimeMsFormat)
		fmt.Fprintln(&out, now, s, len(p))
	} else {
		fmt.Fprintln(&out, s, len(p))
	}

	w := hex.Dumper(&out)
	w.Write(p)
	w.Close()

	if _, err := t.f.Write(out.Bytes()); err != nil {
		return err
	}

	return nil
}

func (t *tee) Send(rq, wq queue.Q) error {
	for b := range rq {
		t.dump(">", b)
		wq <- b
	}

	return nil
}

func (t *tee) Recv(rq, wq queue.Q) error {
	for b := range rq {
		t.dump("<", b)
		wq <- b
	}

	return nil
}

func (t *tee) Close() {
	t.f.Close()
}

func (h *teeHook) where(env env.Env) string {
	if h.file != "" {
		return h.file
	}

	if v := env.GetLocal("tee.file"); v != "" {
		return v
	}

	return teeDefaultFile
}

func (h *teeHook) Open(env env.Env) (interface{}, error) {
	file := h.where(env)
	dir := path.Dir(file)

	if err := os.MkdirAll(dir, 0755); err != nil {
		return nil, err
	}

	tid, sid := env.Get("tunnel"), env.Get("stream")
	name := fmt.Sprintf("%s.%s.%s", file, tid, sid)

	t := &tee{h: h}

	if f, err := os.Create(name); err != nil {
		return nil, err
	} else {
		t.f = f
	}

	return t, nil
}

func newTeeHook(opts opts.Opts) (hook, error) {
	h := &teeHook{
		file: opts["file"],
		time: opts.Bool("time"),
	}
	return h, nil
}

func init() {
	register("tee", newTeeHook)
}